Investigation of aerodynamic characteristics of NACA0012 airfoil design using parabolic arcs

2021 ◽  
Author(s):  
Supriya Devi ◽  
K.V. Nagaraja
Keyword(s):  
Aerodynamic Characteristics ◽  
Naca0012 Airfoil

scholarly journals Understanding of Ice Accumulation and Accretion over an Airfoil

2019 ◽  
Vol 8 (3) ◽  
pp. 1143-1149
Keyword(s):  
Aerodynamic Characteristics ◽  
Civil Aviation ◽  
Flight Safety ◽  
Physical Situation ◽  
Ice Accretion ◽  
Liquid Droplets ◽  
Aircraft Icing ◽  
Naca0012 Airfoil ◽  
Accretion Process ◽  
Ice Accumulation

Since the beginning of civil aviation, icing has been a severe weather hazard for aircraft operation. For many years, the term engine icing has been used to describe ice accreting on exposed engine surfaces as an aircraft flies through a cloud of super-cooled liquid droplets. The concern arising out of aircraft icing is due to its adverse effect on flight safety and hence, for decades, a considerable amount of research is on in the area of icing of aircraft and its components exposed to ice. Experimental verification and some of the key numerical investigations in the area have revealed that aerodynamic characteristics and controllability of an aircraft are affected by the amount and type of ice accretion at different locations. Fundamentally icing of airfoil of an aircraft contributes to decrease in lift force as well as the angle of stall on the wing. This also brings up another situation that is longitudinal instability of the apparatus concerned. It has been a complex physical situation to comprehend the accretion process and its impact. In the present study NACA0012 airfoil geometry has been used to understand the accumulation and accretion process through simulation. The results of total mass of ice accreted with respect to total time of accretion (tice) have been presented

Optimization of NACA 0012 Airfoil Performance in Dynamics Stall Using Continuous Suction Jet

2020 ◽  
Author(s):  
M. Tadjfar ◽  
Siroos Kasmaiee ◽  
S. Noori
Keyword(s):  
Incidence Angle ◽  
Incident Angle ◽  
Active Flow Control ◽  
Optimization Method ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Performance ◽  
Control Parameters ◽  
Velocity Amplitude ◽  
Naca0012 Airfoil ◽  
Sinusoidal Motion

Abstract Many different active flow control methods are used to manipulate the flow field about aerodynamic surfaces in order to obtain the most desirable aerodynamic performance. Among these techniques, boundary layer suction is one of the most effective techniques used to improve aerodynamic performance of the airfoil. In this study, the configuration of a pure suction jet actuator is optimized over an oscillating NACA0012 airfoil at the Reynolds number of 1.35 × 105 to control the dynamic stall behavior. The airfoil was pitched around the quarter-chord location with a sinusoidal motion and the angle of attack was varied between −5 and 25 degrees. Genetic algorithm was implemented as the optimization method. However, since large number of numerical simulations were required for this purpose, an artificial neural network was employed for training a function between the control parameters and the airfoil aerodynamic coefficients. Aerodynamic performance defined as lift-to-drag ratio was chosen as the objective function of the optimization. Location, velocity amplitude, opening length and jet incidence angle were the control parameters of this optimization. It was shown that when the velocity amplitude and opening length were maximum, the airfoil reached its highest performance. Moreover, the aerodynamic characteristics of the airfoil were remarkably improved when the jet incident angle approached to 90 degrees. Placing the suction jet actuator in the range between 3 to 6 percent of the airfoil chord, was found to have the greatest effect on improving the aerodynamic performance. For the optimum configuration, the airfoil separation. It was shown that when the velocity amplitude and opening length were maximum, the airfoil reached its highest performance. Moreover, the aerodynamic characteristics of the airfoil were peaked in the range between 90 to 120 degrees, with 107 having the best performance in our database.

scholarly journals The Influence of Boundary Layer Caused by Riblets on the Aircraft Surface

2020 ◽  
Vol 10 (11) ◽  
pp. 3686
Author(s):  
Hongqing Lv ◽  
Zhenqing Wang ◽  
Jiahao Chen ◽  
Lei Xu
Keyword(s):  
Boundary Layer ◽  
Drag Reduction ◽  
Flow Direction ◽  
Angle Of Attack ◽  
Suction Side ◽  
Aerodynamic Characteristics ◽  
Wall Surface ◽  
Friction Resistance ◽  
Naca0012 Airfoil ◽  
Stall Angle

Drag reduction of riblets is one of the most important problems in drag reduction of non-smooth surfaces. In the past two decades, the use of riblets arranged along the flow direction to reduce frictional resistance has received considerable attention. In this paper, we study the plates with the triangular concave grooves, triangular protrusion riblets, trapezoidal concave grooves, trapezoidal protrusion riblets, and circular concave grooves. The numerical simulation method is used to calculate five kinds of plates with grooves and riblets under multiple working conditions. The results showed that the plates with grooves and riblets generated vortices inside the grooves, which separated the incoming flow from the wall surface, and by increasing the thickness of the boundary layer, greatly reducing the average velocity gradient of the wall surface, compared with the smooth flat plate, the friction resistance is reduced. But, lateral riblets and grooves cause additional pressure resistance, which is one order of magnitude higher than the friction resistance. Then, the triangular concave grooves are arranged on the suction and pressure sides of the NACA0012 airfoil, respectively. We calculated the aerodynamic parameters of the both airfoils, and the standard NACA0012 airfoil from the −8° attack angle to their respective stall attack angles. The results showed that the NACA0012 airfoil with triangular concave grooves on the suction side reduced the aerodynamic characteristics of the standard NACA0012 at a small angle of attack, but the stall angle of attack of the standard NACA0012 airfoil was improved, because the grooves ensure that some gas can flow normally on the suction side and delay the separation of the boundary layer. The NACA0012 airfoil with triangular concave grooves on the pressure side did not effectively improve the aerodynamic characteristics: lift–drag ratio decreased and stall angle of attack decreased, but it can increase the lift slightly.

Aerodynamic Performance Investigation under the Influence of Heavy Rain of a NACA 0012 Airfoil for Wind Turbine Applications

2012 ◽  
Vol 6 (6) ◽  
pp. 1228-1235
Author(s):  
Eleni C. Douvi ◽  
Dionissios P. Margaris
Keyword(s):  
Flow Field ◽  
Wind Turbine ◽  
Heavy Rain ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Performance ◽  
Spherical Particles ◽  
Discrete Phase Model ◽  
Two Phase ◽  
Naca0012 Airfoil ◽  
The Impact

The study of the prediction of the flow field and aerodynamic characteristics of a NACA0012 airfoil in simulated heavy rain, using a computational fluid dynamics code is presented. The simulation of rain is accomplished by using the two-phase flow Discrete Phase Model, which is available in the CFD code. Spherical particles are tracked through the two-dimensional, incompressible air flow field over a NACA0012 airfoil, at a simulated rain rate of 1000 mm/h and operating at Reynolds numbers Re=1×106 and Re=3×106. To validate the CFD developed model, the results are compared with well-established and published experimental data, showing good agreement. The aim of the work was to show the behavior of the airfoil at these conditions and to establish a verified solution method. Lift and drag coefficients are computed at various angles of attack in both dry and wet conditions and the results are compared to show the effects of rain at airfoil performance. The impact of rain on wind turbine performance is also analyzed. It is concluded that rain causes degradation of aerodynamic performance, especially lift is decreased and drag is increased.

scholarly journals Unsteady aerodynamics modeling using Volterra series expansed by basis function

2018 ◽  
Vol 198 ◽  
pp. 03002
Author(s):  
Senlin Chen ◽  
Zhenghong Gao
Keyword(s):  
Basis Function ◽  
Volterra Series ◽  
System Modeling ◽  
Unsteady Aerodynamics ◽  
Stable Solution ◽  
Aerodynamic Characteristics ◽  
Higher Order ◽  
Second Order ◽  
Nonlinear System Modeling ◽  
Naca0012 Airfoil

Unsteady aerodynamics modeling must accurately describe nonlinear aerodynamic characteristics in addition to unsteady aerodynamic characteristics. The Volterra series has attracted increasing attention as a powerful tool for nonlinear system modeling. It is essential to incorporate the influence of the second-order Volterra kernel or higher-order kernels to build a nonlinear unsteady aerodynamics model. The main difficulty in the identification of higher-order kernels is that the number of parameters to be identified increases exponentially with the order of a kernel. This paper expands the Volterra kernels with the four-order B-spline wavelet on the interval as the basis function, converts the problem into the solution of low-dimensional equations, and obtains a stable solution. A nonlinear unsteady aerodynamics model is built by identifying the second-order and third-order kernels of the lift, drag, and pitching moment coefficients of the NACA0012 airfoil. Then the model is verified at different reduced frequencies using CFD.

Numerical Investigation of Flow past a Wavy Airfoil

2011 ◽  
Vol 110-116 ◽  
pp. 4269-4275
Author(s):  
K. Lam ◽  
Y.F. Lin ◽  
Y. Liu ◽  
L. Zou
Keyword(s):  
Numerical Investigation ◽  
Lift Coefficient ◽  
Angle Of Attack ◽  
Aerodynamic Characteristics ◽  
Large Eddy Simulations ◽  
Wavy Surface ◽  
Naca0012 Airfoil ◽  
Large Eddy ◽  
Stall Angle ◽  
Coefficient Reduction

The effect of the wavy surface on the aerodynamic characteristics of an airfoil is studied using the large eddy simulations. A more gentle lift characteristic is obtained during stall. For angles of attack less than the baseline stall angle of a NACA0012 airfoil, a lift coefficient reduction was observed for the wavy airfoils, while the lift coefficient increases up to 23% greater than that of a NACA0012 airfoil when the angle of attack is larger than the baseline stall angle of the NACA0012 airfoil.

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